Lassa virus lasv belongs to the mammarenavirus genus family arenaviridae and causes severe hemorrhagic fever in humans. What you need to know about lassa fever 6 april 6 april 6 april 6 april 6 april 6 april 6 april estimated number of lassa fever cases in west africa each year death rate from ebola death rate from lassa fever estimated number of deaths lassa fever is caused by a virus that is found in west africa. Pdf diagnostic systems for lassa fever lf, a viral hemorrhagic fever caused by lassa virus. Pdf lassa virus lasv and ebola virus ebov infections are important global. Lassa virus is endemic to west africa and causes hemorrhagic fever in humans. The epitopes of the lassa virus lasv surface glycoproteins recognized by. Lassa fever is a viral illness that typically occurs in west africa. The features of severe clinical disease may include bleeding andor. Started in 1995, this collection now contains 6767 interlinked topic pages divided into a tree of 31 specialty books and 732 chapters. Javascript is disabled or is not supported by your browser. How does the virus infect the body and move from host to host. Clinical description and pathogenesis of lassa fever. Details of lassa virus structure could inform development. Casepatient 4, a pregnant nurse, had a spontaneous abortion and died on day 9 of hospitalization.
Mastomys rats infected with lassa virus do not become ill, but they can shed the virus in their urine and faeces. Lassa fever, also known as lassa hemorrhagic fever lhf, is a type of viral hemorrhagic fever caused by the lassa virus. Lassa fever by carly brown discovery john frame 1969 collaborated with yale arbovirus research unit typestructure arenaviridae family spherical lipid membrane singlestranded rna transportation zoonotic hostmultimammate rat genus mastomys person to person transportationcont. Lassa mammarenavirus is an emerging virus and a select agent, requiring biosafety level 4equivalent containment. Lassa fever is a viral hemorrhagic fever caused by a rodentborne arenavirus that is endemic in west africa. Pdf development of recombinant nucleoproteinbased diagnostic. Lassa virus, the causative agent of lassa fever, is a member of the family arenaviridae. The virus can spread between people through direct contact with the body fluids of a person infected with lassa fever, as well. Lassa virus, which is a member of the arenaviridae virus family, causes acute viral hemorrhagic fever.
Diagnostics for lassa fever virus bmj global health. Lassa fever in the netherlands ex sierra leone ecdc. Lassa viruses are ss rna viruses family arenaviridae causing severe haemorrhagic disease cf ebola haemorrhagic disease. The multimammate rat mastomys natalensis is the only known reservoir of lasv. Now including hgtv, food network, tlc, investigation discovery, and much more. For this reason, some items on this page will be unavailable. Determining ribavirins mechanism of action against lassa. The lassa virus is known to cause disease in different organ systems of the human body, with varying clinical manifestations. The lassa virus is transmitted to humans mainly through handling rats, food or household items contaminated by rats urine and faeces.
Lassa infections are treated with the drug ribavirin. Replicon system for lassa virus journal of virology. A sample of lassa had been in this lab, decades before. The mobile unit was used once before, in an outbreak of lassa fever in sierra leone in 1972, when dr. Lassa virus lasv is a member of the old world complex of viruses, genus arenavirus, family arenaviridae, which also includes lymphocytic choriomeningitis virus lcmv and lujo virus. While lassa fever is mild or has no observable symptoms in about 80% of people infected with the virus, the remaining 20% have a more severe multisystem. They are enveloped greenish layer in this image and studded with red protein spikes. The very diverse lasv genome has 4 major lineages associated with different geographic locations.
This is so called because at some point in the disease the patient bleeds. Less commonly there may be bleeding from the mouth or gastrointestinal tract. Lasv, which primarily causes infection in humans, was originally isolated from a missionary nurse in lassa, nigeria in 1969. Lassa fever is one of the hemorrhagic fever viruses like ebola virus, marburg virus, and others unlike ebola virus, lassa fever is not as contagious person to person, nor as deadly lassa virus is typically transmitted by the urine or feces of mastomys rats to humans. Lassa fever was confirmed in casepatients 3 and 4 by rtpcr as well as by igm and igg seroconversion in the surviving patient casepatient 3. Lassa virus may be spread in contaminated medical equipment, such as reused needles. The incubation period of lassa fever ranges from 7 to 21 days 34,58.
Cfx96 deep well realtime pcr detection system biorad. For the majority of lassa fever virus infections approximately 80%, symptoms are mild and are undiagnosed. The rodents shed the virus in their urine and droppings. Sequencing the gp and l gene pcr fragments showed that casepatients 3 and 4 were infected with the. The reservoirs of all three diseases are mainly confined to equatorial africa. At present, there are no food and drug administration fdaapproved drugs or vaccines specific for lasv. Lassa fever lf, an acute viral haemorrhagic fever, is an endemic zoonotic viral infection in west africa countries with up to 15% case fatality rate. Lassa fever annual epidemiological report for 2016 surveillance report12 oct 2018.
Most neutralizing human monoclonal antibodies target novel. Signs and symptoms of lassa fever typically occur weeks after the patient comes into contact with the virus. Pathophysiology and treatment of lassa fever springerlink. Lassa mammarenavirus lasv is an arenavirus that causes lassa hemorrhagic fever, a type of viral hemorrhagic fever vhf, in humans and other primates. Lassa fever is an acute viral zoonotic illness caused by lassa virus, an arenavirus known to be responsible for a severe haemorrhagic fever characterised by fever, muscle aches, sore throat, nausea. General facts viral hemorrhagic fever caused by the arenavirus lassa transmitted from rodents to humans discovered in nigeria, 1969 endemic in portions of west africa seasonal clustering. The clinical disease begins as a flulike illness characterized by fever, general weakness, and malaise, which may be accompanied by. Persistent and latent infections occur if viral genome becomes integrated into the host cell genome. There is no risk of primary infection with lassa virus in community settings in.
Many of those infected by the virus do not develop symptoms. Lassa virus, an arenavirus first isolated in 1969 in jos, nigeria 1, is the cause of lassa. Lassa virus was isolated from the sierra leone case. National notifiable diseases surveillance system nndss note. Pdf lassa and ebola virus inhibitors identified using minigenome. Lassa fever lf is a severe and often fatal hemorrhagic disease caused by lassa virus lasv, a member of the arenaviridae virus family. One wonders why borno state is usually home to a lot of things. Systems division, united states army medical research institute of infectious diseases, fort detrick, maryland. Outside of the case at emory university hospital, there have been six other cases of lassa fever reported in the united states. Lassa virus remains an important cause of illness in west africa and among the. A human antibody from an african survivor teal is shown anchoring to the base of the lassa virus surface protein, locking it in position to prevent the virus.
Unless you live in or have visited certain parts of western africa, or have had close contact with someone who does or has, your likelihood of contracting lassa fever is very low. Sequence variability and geographic distribution of lassa. It is endemic in parts of west africa including sierra leone, liberia, guinea and nigeria. The multimammate mouse mastomys natalensis is the only known nonhuman host for lassa virus monath et al. Lassa fever virus lasv causes acute viral haemorrhagic. Diagnosis of lassa fever and the isolation and management. Lassa fever is an animalborne, or zoonotic, acute viral illness. Lassa virus can cause a hemorrhagic disease called lassa fever and is endemic to western africa. Lassa fever is a severe multisystem disease that often has haemorrhagic manifestations. Lassa fever, marburg virus disease and ebola virus disease are all viral haemorrhagic fevers. It was first reported in 1969 in the town of lassa, in borno state, nigeria.
Ebola, on the other hand, does not yet have an fdaapproved drug used for treatment. Health workers may be infected by direct contact with blood, body fluids, urine, or stool of a patient with lassa fever. Lassa fever, nigeria, 20052008 volume 16, number 6june. Lassa fever was first documented in nigeria, in lassa village of borno state. Natal multimammate mouse is the primary reservoir of lassa virus, found in subsaharan africa. Lassa virus is a member of the old world arenaviruses, and, as such, is endemic in western africa. Kent campbell, an epidemiologist at the at lanta center, developed a. Lassa virus lasv is endemic to parts of west africa and causes highly fatal hemorrhagic fever. Laboratory diagnosis of lassa fever journal of clinical microbiology. Most human infections result from zoonotic transmission. I fled, running until i reached the sidewalk eight floors below, heart pounding, out of breath, sure i was being chased by lassa. Lassa antibody and antigen were found in 96 11% and 46 5%, respectively, of 884 tested mastomys demby et al. Lassa virus is transmitted by the multimammate rat, also known as mastomys natalensis. However, the full extent of lassas endemicity is unknown due to poor mean of contact and communication with the rural villages where lassa is surely seen, a factor that prevents both reporting and treatment of infection.
Lassa fever, marburg and ebola virus doctor patient. Historical lassa fever reports and 30year clinical update. How lassa and ebola are similar but different msnbc. Lassa fever infects an estimated 100,000 to 300,000 individuals in west africa each year and around 5,000 result in death. Lassa virus definition of lassa virus by medical dictionary. Never has a book done anything like that before or since. Neighboring countries are also at risk, as the animal vector for lassa virus, the multimammate rat mastomys natalensis is distributed throughout the region. In 2004, the centers for disease control and prevention cdc reported a fatal case of lassa fever in new jersey. We used reverse transcription pcr and resequencing microarrays.
Details of lassa virus structure could inform development of vaccines, therapies. Here, highthroughput screening of an fdaapproved drug library was performed against lasv entry by using pseudotype virus bearing lasv envelope glycoprotein gpc. Lassavirus definition of lassavirus by medical dictionary. Pdf prevalence of lassa virus among rodents trapped in. When symptoms occur they typically include fever, weakness, headaches, vomiting, and muscle pains. The disease is highly contagious and spread like wild fire. Redeemers varsity develops 10mins lassa fever testkit. However, their contagiousness means that the potential for outbreak is real if imported cases go undetected. To facilitate the functional analysis of this virus, a replicon system was developed based on lassa virus strain av. Though a rodentborne infection, it can also be transmitted from person to person during the care of sick relations or more commonly in health care settings as a nosocomial infection. Lassa fever annual epidemiological report for 2017 surveillance report11 jun 2019.
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